/**
 * Created by Administrator on 2016/8/5.
 */
var code ; //在全局定义验证码

//产生验证码
window.onload = function createCode(){
    code = "";
    var codeLength = 4;//验证码的长度
    var checkCode = document.getElementById("code");
    var random = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R',
        'S','T','U','V','W','X','Y','Z');//随机数
    for(var i = 0; i < codeLength; i++) {//循环操作
        var index = Math.floor(Math.random()*36);//取得随机数的索引（0~35）
        code += random[index];//根据索引取得随机数加到code上
    }
    checkCode.value = code;//把code值赋给验证码
};
